Alkylation process



Feb. 19, 1952 c. E ADAMS Erm.

ALKYLATION PROCESS Patented Feb. 19, 1952 z,55,9s3 ALKYLATION PROCESS Chester E. Adams, Highland, Ind., and Wayne A. Proell and Edward G. Ballweber, Chicago, Ill., assignors to Standard Oil Company, Chicago, Ill., a corporation of Indiana Application December 4, 1948, Serial No. 63,582

This invention relates to a novel process for the alkylation of aromatic hydrocarbons wherein the alkylating agents are liquid olenic hydrocarb-on fractions derived from processes for the hydrogenation of carbon monoxide (so-called hydrocarbon synthesis or HCS) and wherein organic sulfonic acids are employed as alkylation catalysts.

Olen fractions, including olen polymers, which contain no oxygenated organic compounds (oxy compounds) can readily be employed to alkylate aromatic hydrocarbons in high yields in the presence of a wide variety of catalysts. Surprisingly, we have observed that certain oxy compounds in HCS olen fractions exhibit substantial inhibiting or poisoning effects on conventional alkylation catalysts such as aluminum chloride, phosphoric acid and sulfuric acid and that the employment of HCS olefin fractions containing oxy compounds for the alkylation of aromatic hydrocarbons leads to low yields of alkymers and low alkylation reaction rates.l A1- though we do not choose to be bound by any theory, our observations on the effects ofHCS olefin fractions containing oxy compounds on conventional alkylation catalysts have led us to the belief that the poisoning effects are at least two-fold, viz., (1) water produced by the dehydration of some of the oxy compounds in the HCS olen fraction dilutes the alkylation catalyst or reacts therewith. (2) oxy compounds containing the carbonyl group such as ketones, aldehydes, etc. exert a poisoning effectA on conventional alkylation catalysts apparently by the formation of complex compounds therewith.

The crude HCS olefin fractions which We employ in our alkylation process are derived from processes in which carbon monoxide is reduced by hydrogen to produce a variety of gaseous, liquid and solid hydrocarbons in the presence of eighth group metal catalysts, particularly iron, cobalt and nickel catalysts. The synthesis gas, consisting essentially of a mixture of carbon monoxide and hydrogen, is produced by partial oxidation of natural gas or other hydrocarbon gas, suitable operating conditions being, for example, a temperature of about 2500 F. and a pressure of about 250 p. s. i. g. Synthesis gas may also be produced by conventional processes of reforming natural gas with steam in the presence --of a catalyst; when desired, both the oxidation .l and reforming processes may be employed to gen- 8 Claims. (Cl. 260-67-1) erate synthesis gas. The H2 CO ratio in the synthesis gas may be adjusted as desired, usually to a ratio between about 2:1 and about 5:1 in the reactor. A variety of iron-containing catalysts may be employed. The catalysts may be prepared by the reduction of fused iron oxides, mill scale, or' pyrites-ash, and may be sintered before or after reduction to obtain improved activity and life.l The iron catalysts are suitably promoted by small amounts of alkali metal components such as KOH, H2003, KF or the corresponding sodium compounds. A suitable catalyst, for example is the commercial ammonia synthesis catalyst frequently employed in the United States, known as the C. C. C. catalyst; essentially this catalyst is iron promoted by small amounts of alkali. Synthesis can be effected in reactors utilizing a fluidized iron catalyst bed at temperatures between about 450 and about 700 F. and pressures between about 200 and about 500 p.s.1.g.

Among the hydrocarbon products produced in the above-described synthesis operation are olefinic hydrocarbon fractions which contain parafiin hydrocarbons o-f approximately the same carbon number and boiling range and, in addition, a substantial amount of preferentially oil-soluble, neutral oxygen-containing organic compounds such as aldehydes, ketones, esters, acetals, ethers, alcohols and the like. We have observed that these olenic hydrocarbon fractions, with which the preferentially oil-soluble oxygen-containing organic compounds are associated. contain, on

the average. 7 and more carbon atoms per molecule of the hydrocarbons present. 'l'he oxygenated compounds present in the above-mentioned Synthol olefin hydrocarbon fractions cannot be removed to any satisfactory degree by simple washing with water, alkalies or specific group reagents, for example, aqueous sodium bisulte for the removal of carbonyl compounds.

The proportion, and possibly to some extent the nature of the oxygenated compounds produced in the iron-catalyzed HCS process, will naturally depend upon and vary with the specic catalyst; catalyst age and operating conditions employed. Table 1 sets forth data concerning the composition of a typical iron-HCS olen fraction. It can readily be calculated from the data in Table 1 that the oxy compounds concentration in the total olefin fraction was about 13.3 weight per cent.

TABLE 1 Total Oxy. Hydroxyl Carbonyl Number fractlon yravlty Oxygen tf.)f Jel'zcnt Wtf JeLCent Wtf cel. ent by Difference 8.8 0.655 1. 3. 6 l. 3 2. 3 14.0 1. 389 0.687 0.83 3. 8 1.6 3.3 -l. 1 14. 0 1. 4087 0.726 2.10 11. 3 3. 9 4. 7 2. 7 13. 7 1. 4115 0.737 2.03 12. 7 V 6. 0 11. 6 .1, 4230 0. 764 1.97 14.0 9. 3 6. 5 -L 9. 7 1. 4350 0. 790 2. 46 19. 7 '9. 0 6. 2 4.5 7. 4 l. 4430 0. 804 2. 73 24. 2 12.0 6. 2 6. 0 4. 7 1. 4487 0. 822 2. 76 27. O 14.0 6.1 6. 9 3. 7 1. 4540 0. 831 2. 58 27.4- 15.0 5. 7 6. 7 2. 1. 4575 0. 836 2. 43 2B. 0 6. 1 1. 6 1.4613 0.842 2. 3 28. 4 18.0 5. 9 4. 5 1.1 1.4638 0.844 2.1 28.2 16.5 5.7 6.0 1.4660 0.848 2.5

The olenic hydrocarbon content of the nor-- mally liquid HCS olen fractions often ranges between about 50 and about 75-percent by Yweight and the concentration of oxy compounds ranges from about to about 30 Weight percent.

Although, aswe havepointed out above, crude HCS olein fractions cannot be used for the 'alkylation of aromatic hydrocarbons in the presence of conventional catalysts, We have found that organic sulfonc acids can be employed as alkylation catalysts providing that Water be removed from the alkylation zoneY during the course of the alkylation operation to maintain substantially anhydrous conditions in the alkylation zone. Also, if it is desired to maintain the activity of the sulfonic acid catalyst it is desirable, from time to time, toremove the oxy compounds which are dissolved by and accumulate in the catalyst phase. Since sulfonic acids function not merely as alkylation catalysts but also as selective solvents for oxy compounds in the process of this invention, the present process yields alkymers which are substantially free of oxy compounds.

The presence of oxygen-containing organic compounds in aromatic alkymers derived from HCS olenic hydrocarbon fractions is highly undesirable. We have noted that some fractions of oxygenated organic compounds obtained from HCS olens possess dark color. Sulfonation 'of the aromatic alkymers to produce detergents is usually conducted With concentrated or fuming sulfuric acid, in the course of Which oxygen-containing organic compounds undergo resinication and darkening, resulting in the production of dark-colored, resin-containing sulfonic acids.

A Wide variety of organic sulfonic acids may be employed as alkylation catalysts and solvent media in4 the process in the vpresent invention. 'Thus,` we may employ strongly acidic 'alkanesulfonic acids, particularly those having 1 to 5 carbon atoms, inclusive, in the molecule, and their mixtures, although We may employ higher alkanesulfonic acids. Aryl sulfonic acids such as benzenesulfonic, toluenesulfonic, xylenesulfonic, naphthalenesulfonic, phenolsulfonic, chlorobenzenesulfonic, t-butylbenzenesulfonic and the like may also be employed. Also employable in the process of the present invention are chloroalkanesulfonic acids, which are produced to vsome extent by the hydrolysis of the products of reaction of sulfur dioxide and chlorine with paraiiin hydrocarbons having 3 or more carbon atoms and with cycloparailin hydrocarbons. Ordinarily We prefer to employ a strongly acidic sulfonic acid which will be present largely or wholly as a liquid phase 'under the alkylation process conditions selected for a particular set of reactants. Par- .accompanying figure.

ticularly, we prefer to employ hydrocarbon sulfonic acids as catalysts and solvent media for the alkylation process here under consideration, such as Ci-Cs alkanesulfonic acids. It is convenient to use normally liquid sulfonic acids or sulfonic acids having melting Apoints below about 55 C. as alkylation catalysts. The employment of liquid or readily liqueable sulfonic acids as catalysts greatly simplifies the separation procedure following the alkylation processas will be discussed in some detail hereinafter in connection with'the It should also 'be `noted that Avthe accumulation "of Oxy compounds inthe sulfonic acid catalysts tends to cause considerable reductions in melting points.

As charging stocks tobealkylated, we may'employ monocyclic aromatic 'hydrocarbons A:such as benzene, toluene, xylenesjnand 'isopropylbenzenes, mor p-cymene, ethylbenzene, ethyltoluene, pseudocumene, butylbenzenes, amylbenzenes, cyclohexylbenzene and the like. We may also employ polycyclic aromatic hydrocarbons as 'the charging stock to be alkylated, for exam- .ple naphthalene, methylnaphthalenes, dimethylna'phthalenes, amylnaphthalenes, anthracene, diphenyl andthe like.

A vparticularly desirable application of 'the process of our invention is to the preparation of alkymers which yield high quality detergents upon sulonation and neutralization, i. e., socalled detergent alkymers. To this end, the preferred charging stocks are monocyclic aromatic hydrocarbons containing 6 to 10 carbon atoms, inclusive, in the molecule and iron-catalyst HCS oleiin fractions containing one or a mixture of mono-olehs having between 7 and about 15 carbon atoms,'preferably '10 to V15 'carbon atoms,

inclusive, in the molecule.

While the preparation of detergent alkyl aro- I matic hydrocarbons represents a highly desirable 'from the alkylation reaction zone since the/'addi- "tion of v-chemical 'water-combining reagents "is sually accompanied by 'more or less 'deleterious eii'ects upon the catalyst and moreover it intro--V duces great complications in the separation of the alkylation reaction mixture.

We prefer to remove water from the alkylation reaction zone at substantially the rate at which it is formed, but it is possible to effect a somewhat lower rate of Water removal from the alkylation reaction zone Without foregoing entirely the advantages of increased reaction rate and higher yield of alkymer. We prefer to effect removal of Water at a rate such that the amount of water present in the alkylation reaction zone at any one time does not exceed about 5 Weight percent present based upon the sulfonic acid catalyst employed.

It is desirable to remove water from the alkylation reaction zone as a minimum boiling azeotrope. Water forms minimum boiling azeotropes With low boiling monocyclic aromatic hydrocarbons such as benzene and toluene. Thus, by using an excess of the monocyclic aromatic hydrocarbon to` be alkylated and by effecting the alkylation reaction by reluxing the reactionmixture, it is possible to distil overhead from the reaction mixture an aromatic hydrocarbon-Water minimum boiling,r azeotrope which may be condensed outside the reaction zone to form a lower '6 water layer and an upper aromatic hydrocarbon layer which may be recycled to the alkylatlon reaction zone to ald in carrying off further quantities of Water therefrom, 5 It may also be desirable to add materials t0 the alkylation reaction zone which form minimum boiling azeotropes with water and which are chemically inert under the alkylation reaction conditions. Suitable materials include ethyl acetate, methyl ethyl ketone, chloroform, cyclohexane or the like. Because of its obvious simplicity and economy We prefer that method of Water removal from the alkylation zone which entails the use of an excess of the alkylatable hydrocarbon which forms a minimum boiling azeotrope with Water.

When the reactants in the alkylation zone boil at a suiciently high temperature and do not form minimum boiling azeotropes with water, it is possible to distill water directly from the alkylation reaction zone by maintaining a sufficiently high temperature therein and, if desired, blowing inert gases such as nitrogen, methane or CO2 therethrough.

1n order to illustrate but not unnecessarily to limit the scope of our invention, anumber of examples thereof are tabulated below (Table 2).

See footnotes at end of table.

TABLE 2 Run No 1 2 3 4 5 6 7 s HCS Olefin:

Carbon N0 12 12 12 12 12 12 12 Boiling Range, F 406-412 391-397 391-397 391-397 391-397 391-397 40G-414 406-414 (l0 and 90% A. S

st (1) EtSOaH EtSOgH EtSOQH EtSO;H EtSOgH EtSOgH EtSOsH 100 100 100 100 100 100 100 100 T220 T223 T223 T223 T223 T223 T223 T223 16 32 5 32 37 64 65 327 375 339 355 355 360 387 388 650 Operating Conditions:

H2O Trap-out No Yes Yes Yes Yes Yes Yes Yes Temp., "F 230-241 230-241 230-241 230-241 230-241 230-241 230-241 Time,H0urs 1.25 s5 a5 3 35' '5 x5 s5 Reaction Rate, W. per cent Oleiin Disappearance after:

1 our 8 47 28 50 83 97 5 hours 19 81 69 81 89 97 84 Recovery, w. per cent on HCS fraction:

Catalyst Layer 13 32 24 34 71 70 352 W. per cent dissolved materials 2 5 3 3 3 208 183 186 150 178 156 83 60 33 39 37 34 25 25 22 63 53 41 69 93 85 15 24 24 40 20 28 23 otal 320 340 329 305 375 372 568 Heart Alkymer, per cent of theor... 4 18 25 4 71 4 60 4 46 i 78 7 90 7 82 Per cent H2O in Catalyst:

Before Reaction 0 l 0 0 0 0 0 0 After Reaction 0 0 0 0 0 0 0 Rim N0. 9 10 11 12 13 14 l5 16 HCS Olefn:

Carbon No 12 l2 l2 l2 Boiling Range, "F 391-397 406-414 391-397 391-397 391-397 391-397 391-397 391-397 (10 and 90% A. S. T. M.) Catalyst EtS03H EtSOgH EtSOaH EtSOI EtSOgH EtSOaH EtSOaH EtSOiH Chae, W. per cent on HCS fraction:

S fraet 100 100 100 100 100 100 1 Aromatic H C (2) T223 T223 T223 T223 T223 T223 T223 T223 32 33 65 64 9 69 1 63 11 57 l2 74 Total 355 356 388 387 392 386 380 397 Operating Conditions:

' H2O Trap-out No No No Yes Yes Yes Yes Yes Temp., F. 230-241 230-241 230-241 230-241 230-241 230-241 230-241 230-241 Time, Hours 3 5 3 5 5 Reaction Rate, W. per cent Olefln Disappearance after:

1 hour 58 22 65 81 79 74 74 71 5 hours 81 47 89 90 90 88 86 82 Recovery, w. per cent on HCS fraction:

Catalyst Layer 33 24 68 70 64 58 49 80 W. per cent dissolved materials 15. 7 22 20.6 22.4 27. 5

' Run No 17 18 "Hes olefin;

TABLE 2-continud cid .Aromatic H. C. (Unrea Light Alkymcr Heart Alkymer Heavy Alkymer Total Heart Alkymer, per cent of theor. Per cent H2O in Catalyst:

Before Reaction EtSOaH Yes Yes Yes Yes Yes Yes 1 hour 78 75 5 hours 87 89 Recovery, W. per cent on HCS fraction:

Catalyst Layer 63 71 W. per cent dissolved materials 19.1 Oil ayer:

Light Alkymer Heart Alkymer Heavy Alkymer otal Heart Alkymer, per cent of theor Per cent H in Catalyst:

Before Reaction After Reaction 1 95%H1SO4 1 T toluene; B benzene.

1 Exclusive of 0.5 hour allowed for addition of olefin to mixture of aromatic and catalysts.

Recovered catalyst from Run 4 (2,8 w. per cent acid) plus 13 w. per cent fresh acid catalyst.

7 Based on 67% oleiin in HCS olen fraction charged. a Recovered catalyst from Run 9 (29 w. per cent acid).

Recovered catalyst from Run 12; catalyst comprised 16 w. per cent dissolved oxys and aromatic hydrocarbons. 1 Recovered catalyst from Run 13; catalyst comprised 22 w. per cent dissolved oxys and aromatic hydrocarbons. 11 Recovered catalyst from Run 14; catalyst comprised 21 w. per cent dissolved oxys and aromatic hydrocarbons.

11 Catalyst pretreated with HCS olefin equivalent to 12 runs. 13 Regenerated catalyst from Run 16.

1 In addition, 2 w. per cent water, based on HCS fraction was recovered from thewater trap. 11 Based on 73.5% oleiin in HCS olen fraction charged and average rn. w. of 154. 1 Based ou 64% olelln in HCS olen fraction charged and average n1. w. of 202.

17 Based on 70% oleln in HCS olen fraction charged.

1! SO2 was blown through the HCS oleilu fraction charged.

1 Boiling point under a pressure of 5 mm. of mercury.

10 Toluene sulfonic acid.

The procedure employed in carrying out the examples was to mix the aromatic hydrocarbon and sulfonic acid catalyst and to carry out the alkylation reaction by agitating and refluxing the mixture while adding the HCS olen fraction gradually thereto. Usually the olen fraction was added over the course of one-half to one hour and refluxing and agitation was thereafter continued for about 5 hours. In the examples in which a water trap Was used, an azeotrope of Water and aromatic hydrocarbon Was distilled continuously from the reaction mixture, condensed and sent to a trap or separating vessel, whence Water was discharged from the reaction system and the aromatic hydrocarbon Yupper layer was recycled to the reaction zone. In the ex- 4amples in which no Water trap was employed, the

entire vapor stream evolved lfrom the reaction mixture was condensedand recycled to the reaction zone so that the Water produced by dehydration reactions in the reaction zone remained in the reaction mixture. T he rate of olen disappearance from the reaction mixture was followed by determining bromine titer.

Upon completion of the desired reaction period, the reaction mixture was allowed to cool, whereupon it was separated into two distinct liquid phases, viz., a lower predominantly sulfonic acid layer containing oxy compounds, dissolved aromatic hydrocarbons and, in some instances, water; a liquid layer comprising predominantly alkymer produced in the alkylation reaction and containing some 4dissolved sulfonic acid catalyst. The alkymer layer was neutralized by washing with alkali and was then water washed and fractionally distilled in a highly efficient fractionating column. The heart alkymer fraction consisted of The solubility of benzene in the above acid was 40 volume percent and the solubility of the acid in benzene was 9.6 volume percent. The solubility of toluene in theabove acid was 21.4 volume percent and the solubility of the acid in toluene was 3.9 Volume percent. Obviously, at higher temperatures the solubilities are increased.

In Example 3 wherein 32 weight percent of sulfonic acid based on the olefin fraction was emfractions and aromatic hydrocarbons employed as charging stocks were redistilled before use. The catalyst used was anhydrous except as otherwise noted and was prepared by reiiuxing and agitating catalyst containing a small amount of water with toluene, using a condensate trap for the removal of water. The ethanesulfonic acid catalyst used in Examples 2 to 21, inclusive, had the following analysis before dehydration with toluene:

. Per cent Sulfonic acid 96.6 Sulfuric acid 1.0

Water 2.2 Ash 1 0.05

The ethanesulfonic acid catalyst employed in Examples 22 and 23 contained 99 percent ethanesulfonic acid.

Referring to Example 1 of Table 2, it will be noted that the employment of concentrated sulfuric acid led to a low yield of heart alkymer. This example typies the results obtained by the use of sulfuric acid asa catalyst in the alkylation of aromatics with HCS oleiin fractions containing oxy compounds.

In Example 2, in which ethanesulfonic acid was employed as the catalyst, a low reaction rate and low yield of heart alkymer were obtained because of the low concentration of catalyst,viz. 16 Weight percent based on the HCS olen fraction. It was observed in this example that the reaction mixture was a homogeneous solution, whereas in succeeding examples wherein 32 weight percent of even more ethanesulfonic acid was employed for the alkylation of toluene, the reaction mixture contained two distinct liquid phases. It appears from a comparison of Example 2 with Example 3 and others in which a greater catalyst concentration was employed, that it is desirable that the The solubility of benzene and toluene in ethanesulfonic acid of the following composition have been determined at about room temperature (20 C.).

ployed and in which water was continuously trapped out 0f the vapors rising from the reuxing reaction mixture, both a high reaction rate and a high yield of desired alkymer were obtained. In Example 4 the catalyst layer separated from Example 3 was employed with fresh charge of reactants. Due to the loss of catalyst by solution in the hydrocarbon phase in Example 3, the actual concentration of catalyst in Example 4 was 27 -weight percent based on HCS olefin fraction. With the reduction in the amount of catalyst, the rate and yield were somewhat reduced in Example 4 as compared with Example 3. In Example 5 the catalyst used was that recovered from Example 4 fortied withfresh ethanesulfonic acid. However, a rather low yield of heart alkymer was obtained, possibly vdue to the increased concentration of oxy compounds which were dissolved in the catalyst layer in the course of the three examples.

Examples 6, 7 and 8 indicate that very high yields of heart alkymer and high reaction rates are obtainable by the employment of a relativelyv large proportion of catalyst. In Example 8 the employment of a very large excess of catalyst (327 weight percent based on olefin) oiered no improvement over the employment of 65 weight percent of catalyst (Example '1), which appeared to be about the optimum in that reaction system. t

The importance of removing water from the reaction zone during the course of the alkylation will be apparent from a comparison of Examples 9, 10 and 11, wherein water was not trapped or otherwise removed from the reaction mixture, with the other examples in which water trapout was employed. It will be noted from a comparison of Example 9 with Example 3 that the accumulation of as much as 4 weight percent of water in the catalyst caused a significant reduction in the yield of heart alkymer. A comparison of Example 11 with Example 7 illustrates this same point. When the concentration of water in the catalyst was allowed to rise above 4 or 5 percent, the reductions in reaction rate and yield of heart alkymer became severe, as shown inExample 10. k

`Examples 12 to 1'7, inclusive, illustrate life studies of the sulfonic acid` alkylation catalyst.

In Examples 12 to 15, inclusive, a given amount of fresh catalyst was used in an alkylation reaction and the recovered catalyst was recycled in subsequent alkylation reactions until some appreciable decrease in yield, which was not a consequence of loss of catalyst by dissolution in hydrocarbons,`became apparent. In Examples 12 to 15, because of loss of catalyst to the hydrocarbon oil phase it was not possible to determine the eiect of a large amount of oxy compounds in the catalyst phase by extended reuse of the catalyst with periodic fortication with fresh catalyst. In Examples -16 and 17, the catalyst was intimately contacted with a large pose of Examples 16 and 1'! was to obtain van approximation of the effect of a large quantity of oxy compounds in the catalyst phase on the catalyst efficiency.

The yield of heart alkymer in Examples 12 to 15 began to drop appreciably in the fourth reaction (Example 15). Yields of light alkymer remained reasonably constant throughout Examples 12 to 15, due to the complete conversion of olefin, while the yield of heavy alkymer was increasing rapidly in the fourth reaction (Example y15). The observed decrease in yield was not due to reduction in the quantity of sulfonic acid catalyst as will be aparent from a cornparison of Example l with Examples 3 and 4 and must, therefore, be attributed to the increasing concentration of oxy compounds inthe catalyst phase. It will be noted that the concentration of dissolved materials in the catalyst phase increased from 15.7 weight percent in Example 12 to 22.4 weight percent in Example 15.

To prepare the catalyst employed in Example 16, a two phase mixture of 130 g. of ethanesulfonic acid, 1560- g. of the HCS olefin fraction times the amount generally employed .in the examples) and 684 g. of n-heptane was heated at 240 F. and stirred for 5 hours, using a trap to remove water from the vapors evolved from the mixture. Heptane was incorporated in the catalyst preparation mixture to remove water as a minimum boiling azeotrope. The mixture was then allowed to settle and cool to room temperature, the liquid catalyst layer was Vseparated and again treated by the above procedure. The total water recovered from both treatements of the catalyst was 31 ml.

The yield of heart alkymer in Example 16 was '70 percent of theoretical although the catalyst employed .contained oxy compounds in a concentration calculated to be equivalent to the concentration expected after the employement of the catalyst in .twelve alkylation reactions. The yield of heart alkymer in Example 16 was the same as that which was obtained after four recycle alkylations, as will be noted Vby comparison with Example 15. It is desirable, therefore, to employ a sulfonic acid catalyst having a re1- atively small concentration of dissolved oxy compounds, preferably not more than about weight percent.

The used catalyst derived from Example 16 was heated to 280 F. to destroy oxy compounds. It proved to beimpossible to remove water from the catalyst and the attempted regeneration was therefore considered unsuccessful.

In a further study of the regeneration of the used catalyst vderived from Example 1'6 it `was found that the addition of water inarnounts of 5, l0 and 15 percent by volume effected only partial separation of an aqueous catalyst -phase from an oil phase. With the addition of volume percent of water to the catalyst derived from Example 16 it was found possible to separate an aqueous acid phase from 4an insoluble oil. YThe aqueous acid phase was then dehydrated by azeotropic distillation of water'therefrom with toluene. The catalyst thus prepared Ywas employed in Example 17. The insoluble oil derived by the addition of water to the catalyst phase was Washed with water and heated for one hour at 212 'F'. under a pressure of 2 mm. of mercury; no appreciable amount of distillate was produced. The insoluble oil was viscous and opaque and had the following properties Theoretical: 18.6. v

'i Theoretical, assuming one mole 2.6

The analysis was carried out under conditions where the results may be expected to be high.

atom of oxygen per It will be noted from a comparison of Example 1'7 with Example 16 that the yield of heart alkymer was maintained with the use of the regenerated catalysti Examples 18 and 19 are illustrative of the alkylation of toluene with C11-C13 and C14-Cia HCS olefin fractions containing oxy compounds.

Examples 20 and 21 are concerned with the alkylation of benzene with HCS olen fractions. Although the usual redux temperature in the alkylation of toluene was about 240 F., the temperatu'r'e ofthe refiuxing reaction mixture in Exi amples 20 and 21 was only about 185 F. because of the high concentration of benzene in the reac= tion mixture. Because of the relatively low reaction temperature and the incomplete water reroval due to the 10W temperature, the yields of heart alkymer were undesirably low.

By reducing Ithe concentration of benzene the reaction mixture, as in Examples 22 and 23, the reflux temperature of the reaction mixture' was raised from about F. to about 240 F. thereby greatly increasing the reaction rate and yields of heart alkymer. It will be noted that high 'yields of heart alkymer were obtained in Examples 22 and 23 even though only 16 weight percent of ethanesulfonic acid, based on HCS olefin, was used. It appears that the alkylation reaction proceeds rapidly in the presence of even a small amount of catalyst, provided that the cat-f alyst is present in the reaction zone as a distinct liquid phase. With a reduced proportion of aromatic hydrocarbon present in the reaction mixture, a correspondingly reduced amount of catalyst can be used, since aromatic hydrocar-r bons are good solvents for the sulfonic acid catd alyst. In comparing Example 2 with Examples 22 and 23, it will be noted that the high coriJ centration of aromatic hydrocarbon in the' charging stock in Example 2 resulted in the 'formation of a homogeneous reaction solution rand a poor yield of heart alkymer.

Although it would be expected that reducing the mol ratio of aromatic to olen from 4, as in yprevious examples, to 1 as in Examples 22 aridf23` would 'greatly increase the extent of dialkylad tion, this was not found to be the case. A-l though Examples 22 and 23 relate to aromatic :olefin mol ratios of l, we may use ratios between about 0.7 and about 1.5.

Contacting the HCS olefin fraction with SO2 gas, suitably by blowing the liquid olen fraction with SO2 gas, reduces emulsion formation and increases the yield of alkymer in the subsequent alkylation of aromatics with the HCS olefin fraction. The olen fractions in Examples 22; and 23 were thus treated.

Run 24 indicates that toluenesulfonic acid, which is a typical aromatic sulfonic acid and is. available commercially, can be successfully em ployed under much the same operating condi tions as were used with alkanesulfonic acids.

. In Table 3 are presented some physica1 con-v stants of detergent alkymers which were produced by the precess of our invention.

TABLE `s Physical constants of the C11-as1 HCS olefin toluene and benzene alkymers Although certain illustrative embodiments of our invention are represented by the above examples, it should .be understood that our invention is capable of considerable variation. Thus we may employ alkylation temperatures between about 230 and about 300 F., preferably about 240 to 260 F., aromatic olen mol ratios between about 0.'7 and about l0, and an amount of liquid sulfonic acid catalyst sufficient to form a distinct liquid phase under the alkylation reaction conditions. Sucient time is provided to eiect substantial reaction, usually between about one-half to about 8 hours, preferably about 1 to about 5 hours. Important features of the process of this invention are the maintenance of the substantially anhydrous conditions in the reaction zone by trapping water from the vapors evolved by the reaction mixture and theregeneration of used catalyst by the removal of oxy compounds therefrom. i

In order more fully to describe the alkylation process of this invention, reference is made to the accompanying gure which is a flow diagram of one embodiment of our alkylation process. An aromatic hydrocarbon, for example, toluene or a toluene fraction derived from catalytic hydroforming is passed through line I into a reactor II depicted as an autoclave provided with a stirring device I2 and a temperature control jacket I3. A liquid sulfonic acid catalyst, preferably an alkanesulfonic acid catalyst having 1 to carbon atoms, inclusive, in the alkyl group, is passed through lines I4 and IIJ into reactor II. The mixture of aromatic hydrocarbon and sulfonic acid in the reactor are brought to the desired alkylation temperature, which is'usually the reflux temperature of the mixture at about atmospheric pressure, by circulating a heating medium such as steam, hot oil or the like through temperature control jacket I3 of reactor II. An HCS olen hydrocarbon fraction containing oxy compounds is then introduced into the reactor through line I5, the rate of introduction of the olefin being controlled so that excess temperature rises are not encountered in the reaction zone. Usually a period of about 1/2 to 1 hour suiiices for the introduction of olen into the reactor. Following the introduction of olefin into the reaction zone the reaction mixture is rapidly stirred and maintained at the desired reaction temperature, usually between about 240 and about 260 F. for a period of time sufficient to effect substantial alkylation, e. g. between aboutir'.

cient at least to maintaina distinct'liquid cat-l reactor I I.

14 alyst phase, for example between about 3 and about 5 weight percent based on the aromatic hydrocarbon fraction. In the course of the alkylation reaction various of the oxy compounds present in the HCS olen fraction undergo dehydration reactions. vThe aromatic hydrocarbon feed stock and water produced by the dehydration and otherwise introduced with the reactants form minimum-boiling azeotropic mixtures which pass overhead from the boiling reaction mixture through a jacketed line I6 and condenser I1 into a settler I8 provided with a pressure relief line I9 and a weir 20. Water accumulates as a lower liquid phase in settler I8 and is withdrawn therefrom through valved line 2|. The supernatant liquid layer of hydrocarbon flows over weir to the upper part of settler I8 whence it is withdrawn through valved line 22 for recycle to reactor II through line Ill.

Reaction products are withdrawn from reactor II through valved line 23 and cooler 24 into a settler provided with a pressure relief line 216 and a weir 21. By suitable control of cooler 24 the liquid mixture in settler 25 may be main# tained between temperatures of about and about F., suitably at about room temperature. In any event the temperature in settler 25 should be sufficiently high to maintain the catalyst phase in the liquid condition. 'A distinct liquid catalyst layer'is withdrawn from the lower portion of settler 25 through valved line 28, whence all or a portion of the catalyst may be recycled through lines 29 and I4 to reactor II to be reused. A layer of liquid hydrocarbon reaction products flows over weir 21 and accumulates in the upper portion of settler 25, whence it is withdrawn through valved line 30 and heat exchanger 3I into a washing tower 32.

The hydrocarbon reaction products of the pres ent alkylation process dissolve significant proportions of the sulfo'nic acid catalyst, the specific proportion depending upon the composition of the hydrocarbon reaction products, the specic sulfonic acid catalyst and the temperature in settler 25. To prevent undue loss of catalyst and excessive j corrosion of the hydrocarbon fractionating equipment, it is desirable to remove dissolved catalyst from the hydrocarbon reaction products, for example by washing with water,

aqueous alkaline solutions or the like. In general water serves as a suitable washing agent.

`The washing liquid is introduced into the upper portion of tower 32 through a spray line 33. An

aqueous solution of sulfonic acid or sulfonic acid salt forms in the lower portion of 'tower 32 whence it is withdrawn through valved line 34 and may be rejected from the system through valved line 35.

The alkymer and other'hydrocarbon products pass overhead from tower 32 through valved line 36 into a fractionating tower 3l, which maybe of the usual bubble cap or screen packing design. Unreacted aromatic hydrocarbon is withdrawn through valved line 38 and may be recycled to Low boiling alkylate and unreacted olefinic hydrocarbons and non-olenic hydrocarbons which were present in the HCS fraction are Withdrawn from fractionator 3l through valved line 38A. If the olefin concentration in the eiuent of line 38A is sufficiently high it may be ldesirable to recycle this material (by a line not shown) to reactor II; otherwise olens may be segregated from 'this efiluent by conventional methods and the oleiins thus concentrated may be employed in further alkylation-reactions. 'The 1.5. non-ol'enic components of the efiluentin line. 38 may be employed. as fuels in jet engines or reciprocatingpiston engines or may be subjected to further chemical processes such as reforming, cracking, isomerization, alkylation1 etc. to produce -superior non-olennic hydrocarbon fuels.

Aheart alkymer fraction of the desired boiling range is withdrawn from fractionating tower y31 through valved line 39. This fraction, especially when produced by the alkylation of Ce-Cin aromatic-hydrocarbons with Cin-C15 HCS olefin fractions may be sulionated with sulfuric acid, S03 or the like to produce alkyl aromatic sulfonic acids Whose alkali metal, ammonium or amine salts are excellent wetting, washing and detergent agents.

High boiling materials such as polyalkylated aromatic hydrocarbons and HCS olen polymers, boiling above the boiling rangewof the heart alkymer, are withdrawn from tower 3-1 through valved' line 4U.

The kheavy al-kymer may be reacted with a low boiling aromatic hydrocarbon such as benzene or toluene, to produce further quantities of alkymer boiling in the range 4of heart alkymer. Suitable reaction may for example be effected at temperatures of about 80 to 100 F. in the presence of about 5 weight percent AlCla and a small proportion of H-Cl. Other Friedel-Crafts type catalysts may be employed inthe disproportionation reaction.

With continued use, thersulfonic acid catalyst dissolves a substantial proportion of oxycompounds and some aromatic hydrocarbons from the. alkylation charging stocks. tion of these non-acid materials in the acid catalyst phase tends to increase the volume of the catalyst phase, reduces the eective catalyst concentration and impairs the eiiiciency of the sulfonic acid catalyst. It is desirable, therefore, from time to time, to withdraw used catalysts from settler 25 through valved line 28 and line 4I into a settler 42 provided with a pressure relief line 43 and a Weir 44. Water or aqueous sulfonic acid derived from washing tower 32 is passed through valved line 45 into line 4I where it mixes with the used sulfonic acid catalyst. If desired, venturis, knot hole mixers or other mixing devices may be used in line 4I to effect intimate contacting between the used sulfonic acid catalyst and water. The amount of water mixed with the used catalyst should be suilicient to cause the separation of the catalyst into an aqueous sulfonic acid catalyst layer and a layer of water-insoluble oxy compounds and hydrocarbons. The oXy compounds, aromatic hydrocarbons, etc., form a supernatant liquid phase Ain settler 42, pass over Weir 44 and are withdrawn from the settler through valved line 46 into a fractionating tower 41. High boiling oxy compounds are withdrawn from the lowerportion of tower 41 through valved line 48. Aromatic hydrocarbon vapors pass overhead through line '49 and may be discharged from the system through valved line 50v or passed through line 5I and condenser 52 through line I0 forrecycle to reactor I I.

The aqueous layer of sulfonic acid catalyst which forms in the lower portion of settler 42 is withdrawn through valved line 53, whence all or a portion may be passed through valved line 54 and lines I4 and I0 for recycle to reactor VI I. It is preferable, however, to pass all or a major proportion of .the .aqueous catalyst layer from valved line .531into line 55, through heat exchanger 56 into a ystripping tower 51. where sub- The accumulastantlal dehydration. and the removal of volatile materials from the sulfoni'c catalyst are effected. It is desirable to introduce into tower 51 anl inert substance .capable of forming a minimum-boiling azeotrope with water to facilitate the dehydration of the aqueous sulfonic acid catalyst solution. For example, an azeotrope-forming material such as benzene or toluene may be introduced through valved line 58 into line 55 and thence into stripping tower 51. The dehydration of water washings obtained from tower 32 may also be eiected by passing these washings through valved lines 34 and 59 into tower 51. Stripped and dehydrated sulfonic acid catalyst is withdrawn from the lower portion of tower 51 through valved line 60 for recycle to reactor II through lines I4.and I0. A water azeotrope and other volatile materials are withdrawn from stripping tower 51 through valved line 51A. Water and the azeotrope-forming material may be separated from the etiluents of line 51A and the azeotrope-forming materials may be recycled to tower 51 for further use.

It will be appreciated that the accompanying figure merely depicts one of the possible methods of the operation of the alkylation process of our invention. The alkylation process of this invention can be operated batchwise, continuously or semi-continuously. It will be appreciated that our process is not restricted to the use of a stirring autoclave and that other conventional alkylation equipment such as coil or tower reactors such as are employed in petroleum refinery alkylation operations may be employed in the process of this invention.

Having thus described our invention, what we claim is:

1. An alkylation process which comprises contacting a monocyclic aromatic hydrocarbon containing 6 to r10 vcarbon atoms, inclusive, inthe molecule in an alkylation zone with an olenic hydrocarbon fraction containing 7 to 16 carbon atoms, inclusive, in the molecule, said olenic hydrocarbon fraction comprising a substantial amount of preferentially oil-soluble, neutral oxygenated organic compounds including compounds containing a carbonyl group, at least some of said compounds undergoing dehydration under the alkylation reaction conditions, eiecting said contacting in the presence of a liquid alkanesulfonic acid catalyst in a quantity sufficient to form a distinct liquid phase, at a temperature between about 230 F. and about 300 F., and withdrawing water as a vapor from said alkylation zone at a rate suiiicient to preclude the accumulation of water in said zone in an amount inexcess of about 5 percent by weight; based onsaid alkanesulionic acid catalyst.

2. The process of claim l wherein said alkanesulfonic acid contains 1 to 5 carbon atoms', inclusive, in the molecule.

3. The process of claim 2 wherein the olenic hydrocarbon fraction contains 10 to l5' carbon atoms, inclusive, in the molecule. 1

4. An alkylation process which comprises contacting an alkylatable aromatic hydrocarbon in an alkylation zone with an oleiinic hydrocarbon fraction comprising a substantial amount of preferentially oil-soluble, neutral oxygenated organic compounds including compounds containing a carbonyl group, at least some of said compounds undergoing dehydration under the alkylation reaction conditions, effecting said contacting in the presence of a liquid sulfonic acid catalyst in a quantity suicient to form a distinct liquid phase at a temperaturebetween about 230 F. and about 300 F. fora period of time sucient to eil'ect substantial alkylation, withdrawing water as a vapor from said alkylation zone at a rate sufiicient to preclude the substantial accumulation of water in said alkylation zone, cooling at least a portion of the alklation reaction mixture to effect separation thereof into a, liquid phase comprising essentially alkylated aromatic hydrocarbons and a second liquid phase compris-- ing essentially said sulfonic acid catalyst and oxygenated organic compounds extracted by said catalyst from said olenic hydrocarbon fraction, separating said second liquid phase, diluting said second liquid phase with water in quantity sufcient to eiect separation thereof into two immiscible liquid phases, viz., a liquid phase consisting essentially of aqueous sulfonic acid and a liquid phase comprising essentially oxygenated organic compounds, and recycling sulfonic acid catalyst from said liquid phase consisting essentially of aqueous sulfonic acid to said alkylation zone.

5. The process of claim 4 wherein the alkylatable aromatic hydrocarbon is a monocyclic aromatic hydrocarbon containing 6 to 10 carbon atoms, inclusive, in the molecule, said olefinic hydrocarbon fraction contains 7 to 16 carbon atoms, inclusive, in the molecule and said liquid sulfonic acid is an alkanesulfonic acid.

6. A process for the alkylation of benzene which comprises contacting benzene in an alkylation zone with an olenic hydrocarbon fraction containing 7 to 16 carbon atoms, inclusive, in the molecule, said oleiinic hydrocarbon fraction comprising at least about 5 to 30 percent by weight of preferentially oil-soluble, neutral oxygenated organic compounds including compounds containing a carbonyl group, at least some of said compounds undergoing dehydration under the alkylation reaction conditions, maintaining a molar ratio of benzene to said oleiinic hydrocarbon between about 0.7 and about 1.5, effecting said contacting in the presence of an alkanesulfonic acid having l to 5 carbon atoms, inclusive, in the molecule in quantity sufficient to form a distinct liquid phase at a temperature between about 230 F. and about 260 F., and withdrawing water as a Vapor from said alkylation zone at a rate suiiicient to preclude the accumulation of water in said alkylation zone in an amount in excess of about 5 percent by weight,

based on said alkanesulfonic acid catalyst.

7. An alkylation process which comprises contacting an alkylatable aromatic hydrocarbon in an alkylation zone with an olenic hydrocarbon fraction comprising from about 5 to 30 percent by weight of preferentially oil-soluble, neutral oxygenated organic compounds including compounds containing a carbonyl group, at least some of said compounds undergoing dehydration under the alkylation reaction conditions, electing said contacting in the presence of a liquid sulfonic acid catalyst in a quantity suii'icient to form a distinct liquid phase at a temperature between about 230 F. and about 300 F. for a period of time sufcient to enect substantial alkylation, withdrawing water as a vapor from said alkylation zone at a rate suicient to preclude the substantial accumulation of water in said alkylation zone, cooling at least a portion of the alkylation reaction mixture to effect separation thereof into a liquid phase comprising essentially allgvlated aromatic hydrocarbons and a second liquid phase comprising essentially said sulfonic acid catalyst, unconverted aromatic hydrocarbon and oxygenated organic compounds extracted by said catalyst from said oleflnic hydrocarbon fraction, separating said second liquid phase, diluting said second liquid phase with water in quantity sufficient to effect separation thereof into two immiscible liquid phases, Viz., a liquid phase consisting essentially of aqueous sulfonic acid and a liquid phase comprising essentially a mixture of oxygenated organic compounds and unconverted aromatic hydrocarbon, fractionally distilling said unconverted aromatic hydrocarbon from said mixture and recycling aromatic hydrocarbon thus recovered to said alkylation zone, and recycling sulfonic acid catalyst from said liquid phase consisting essentially of aqueous sulfonic acid to said alkylation zone.

8. An alkylation process which comprises contacting an olenic hydrocarbon fraction comprising from about 5 to 30 percent by weight of preferentially oil-soluble, neutral oxygenated organic compounds including compounds containing a carbonyl group, with a molar excess of an alkylatable monocyclic aromatic hydrocarbon having from six to ten carbon atoms per molecule, effecting said contact in the presence of a liquid alkanesulfonic acid catalyst present in suicient quantity to form a distinct liquid phase and at a temperature between about 230 F. and about 300 F. for a period of time sufficient to effect substantial alkylation, distilling monocyclic aromatic hydrocarbons and water, that is formed during alkylation by dehydration of some of the oxygenated compounds, from said alkylation zone at a rate sufficient to preclude the substantial accumulation of water in said alkylation zone, condensing effluent water vapor and aromatic hydrocarbons, separating the aromatic hydrocarbons from the said water, returning the aromatic hydrocarbon to the alkylation zone, withdrawing alkylation reaction mixture from the said zone, cooling at least a portion of the said alkylation reaction mixture, and separating the same into a liquid phase'comprising essentially alkylated aromatic hydrocarbons and a second liquid phase comprising essentially said sulfonic acid catalyst, unconverted aromatic hydrocarbon and oxygenated organic compounds.

CHESTER. E. ADAMS. WAYNE A. PROELL. EDWARD G. BALLWEBER.

REFERENCES CITED The following references are of record in the iiie of this patent:

UNITED STATES PATENTS Number Name Date 1,908,190 Schollkopf May 9, 1933 2,014,766 Isham Sept. 17, 1935 2,244,512 Brandt June 3, 1941 2,409,802 Schmerling Oct. 22, 1946 2,425,572 Slotterbeck Aug. 12, 1947 2,429,622 Hirsch Oct. 28, 1947 2,437,356 Hill Mar. 9, 1948 2,462,793 Lee Feb. 22, 1949 2,465,049 Wolk Mar. 22, 1949 

